@article{MZM_2005_78_5_a13,
     author = {S. B. Vakarchuk},
     title = {Exact {Constants} in {Jackson-type} {Inequalities} and {Exact} {Values} of {Widths}},
     journal = {Matemati\v{c}eskie zametki},
     pages = {792--796},
     publisher = {mathdoc},
     volume = {78},
     number = {5},
     year = {2005},
     language = {ru},
     url = {http://geodesic.mathdoc.fr/item/MZM_2005_78_5_a13/}
}